In recent years, studies on dielectric thin film elements such as a thin film capacitor and an anti-fuse element have been more and more eagerly carried out. A dielectric thin film element includes a capacitance section having a dielectric layer and upper and lower electrode layers that oppose the dielectric layer, and scale reduction and thickness reduction can be made. However, there is a fear that the characteristics of the capacitance section of the dielectric thin film element may be deteriorated by penetration of water. For this reason, dielectric thin film elements having various structures have been proposed in order to improve humidity resistance.
For example, in patent document 1, a dielectric thin film element formed on a substrate 101 and provided with a capacitance section having a dielectric layer 102, a lower electrode layer 103, and an upper electrode layer 104 is disclosed, as shown in FIG. 8. Further, the end of the capacitance section is covered with an insulating protective layer 105 made of an inorganic substance or a resin. Also, the insulating protective layer 105 is covered with a metal thin film 106. The document states that the penetration of water from the outside can be shut out by this lamination structure of the insulating protective layer 105 and the metal thin film 106.    Patent document 1: Japanese Patent Application Laid-open (JP-A) No. 2002-299157 Gazette